The present invention relates to wheel operated winches and, in particular, it concerns a universal wheel operated winch which can readily be connected to the wheels of substantially any modern motor vehicle.
It is a well recognized problem that motor vehicles often become stuck in soft terrain, such as in mud, sand, snow and the like, where the wheels cannot provide sufficient traction to extract the vehicle. Some purpose-built xe2x80x9call-terrainxe2x80x9d vehicles are provided with a dedicated winch for this purpose, but such winches add greatly to the cost of the vehicle and are therefore not widely used.
As long ago as 1923, it was proposed that a motor vehicle could draw itself out of such situations by temporarily attaching a winch drum to the vehicle wheels. Thus the rotation of the wheels which is insufficient to extract the vehicle directly can instead be used to turn the winch. Numerous proposed implementations of this concept may be found in U.S. Pat. No. 1,463,022 to Sepelyak, U.S. Pat. No. 2,240,570 to Oesterheld, U.S. Pat. No. 2,377,881 to Hans, U.S. Pat. No. 4,1135,681 to Cooper, U.S. Pat. No. 4,291,847 to Gilbert, U.S. Pat. No. 4,568,036 to Kearney, U.S. Pat. No. 4,742,971 to Wallace et al., U.S. Pat. No. 4,767,081 to Lau, U.S. Pat. No. 4,778,126 to Spann, U.S. Pat. Nos. 4,836,466 to Peterson and 5,115,994 to Hershberger.
In most of the aforementioned examples, attachment of the winch assembly is a painstaking process involving removal of the bolts securing the wheels and bolting of the winch assembly in place. In the few examples which are easier to attach, the design requires special modification of the wheel itself, or is highly specific to a non-standard wheel design.
One exception to these shortcomings was proposed in U.S. Pat. No. 1,528,058 to Hobson. Here, a winch drum has a square flange with a T-shaped bracket projecting from each comer to engage spokes of a wheel. The device is centered by engagement of a small central hub of the wheel within a central hole in the square flange. This design allows instant fitting of the winch assembly which locks itself by engagement of the T-shaped brackets with the spokes as soon as tension is applied to the cable.
Although the Hobson design offers an advantageous solution for wheels with radial spokes of the type which was apparently prevalent in the 1920""s, it is not readily applicable to modern vehicle wheels. Modern vehicle wheels do not have a knob-like projecting central hub which could be used for centering the device on the wheel. Additionally, modern wheels vary greatly as to the radial positioning and angular spacing of the relatively small openings such that the T-shaped brackets of Hobson, of correctly positioned for a particular wheel design, would not be correctly positioned for the vast majority of other wheels. Furthermore, many modem wheels have non-rectangular arrangements of openings, such as three, five or seven openings spread around the wheel. The rectangular arrangement of Hobson is inherently unsuitable for such cases.
There is therefore a need for a universal wheel operated winch assembly which could rapidly be fit to substantially any modem motor vehicle wheel with minimal labor.
The present invention is a universal wheel operated winch.
According to the teachings of the present invention there is provided, a universal wheel operated winch for convenient attachment to a wheel hub so as to draw a cable by rotation of the wheel, the universal wheel operated winch comprising: (a) a drum providing a substantially cylindrical outer surface configured for receiving a cable wound thereupon, the drum having a central axis; (b) at least three rigid arms, each terminating in an end portion configured to engage an edge of an aperture in a wheel hub, the rigid arms adjustably cooperating with the drum such that a radial distance from the end portion to the central axis may be varied; and (c) a clamping mechanism, associated with the drum, and configured to selectively clamp the rigid arms in a substantially fixed position relative to the drum.
According to a further feature of the present invention, the drum features a clamping surface provided with a plurality of substantially radial grooves angularly-spaced about the axis and configured for receiving the rigid arms, and wherein the clamping mechanism includes a clamping block deployed with a surface facing, and selectively closable towards, the clamping surface so as to clamp the rigid arms within the radial grooves.
According to a further feature of the present invention, the clamping surface is substantially conical.
According to a further feature of the present invention, the plurality of substantially radial grooves includes sets of radial grooves angularly-spaced about the axis at multiples of substantially 360xc2x0/n for at least two different integer values of n not less than 3.
According to a further feature of the present invention, each of the rigid arms has a substantially circular cross-section.
According to a further feature of the present invention, each of the rigid arms is mechanically linked to the drum via a pivotal connection.
According to a further feature of the present invention, the clamping mechanism is configured to impose a substantially uniform limitation on the radial distance of the end portion for each of the arms from the central axis.
According to a further feature of the present invention, the clamping mechanism is configured to displace the at least three rigid arms pivotally about the pivotal connections to positions in which the end portion for each of the arms is at least a given minimum radial distance from the central axis.
According to a further feature of the present invention, the at least three rigid arms are implemented as at least six rigid arms, the pivotal connections being configured to allow each of the rigid arms to be selectively pivoted to an inoperative position.
According to a further feature of the present invention, the at least six rigid arms includes a first group of three of the rigid arms angularly spaced at an angle of substantially 120xc2x0 to each other and a second group of the four rigid arms angularly spaced at an angle of substantially 90xc2x0 to each other.
According to a further feature of the present invention, the pivotal connection of at least one of the rigid arms is implemented by pivotal mounting of the rigid arm on an arcuate rod which approximates to an arc of constant radius about the central axis, the at least one rigid arm being slidable along the arcuate rod, thereby permitting adjustment of an angular spacing between at least two of the rigid arms about the central axis.
There is also provided according to the teachings of the present invention, a universal wheel operated winch for convenient attachment to a wheel hub so as to draw a cable by rotation of the wheel, the universal wheel operated winch comprising: (a) a drum providing a substantially cylindrical outer surface configured for receiving a cable wound thereupon, the drum having a central axis; and (b) at least three rigid arms, each mechanically linked via a pivotal connection to the drum and terminating in an end portion configured to engage an edge of an aperture in a wheel hub, the pivotal connection being configured such that pivoting of the rigid arm varies a radial distance from the central axis to the end portion.
According to a further feature of the present invention, there is also provided a mechanical actuator associated with the drum and configured to impose a substantially uniform limitation on the radial distance of the end portion for each of the arms from the central axis.
According to a further feature of the present invention, there is also provided a mechanical actuator associated with the drum and configured to displace the at least three rigid arms pivotally about the pivotal connections to positions in which the end portion for each of the arms is at least a given minimum radial distance from the central axis.
According to a further feature of the present invention, the at least three rigid arms are implemented as at least six rigid arms, the pivotal connections being configured to allow each of the rigid arms to be selectively pivoted to an inoperative position.
According to a further feature of the present invention, the at least six rigid arms includes a first group of three of the rigid arms angularly spaced at an angle of substantially 120xc2x0 to each other and a second group of the four rigid arms angularly spaced at an angle of substantially 90xc2x0 to each other.
According to a further feature of the present invention, the pivotal connection of at least one of the rigid arms is implemented by pivotal mounting of the rigid arm on an arcuate rod which approximates to an arc of constant radius about the central axis, the at least one rigid arm being slidable along the arcuate rod, thereby permitting adjustment of an angular spacing between at least two of the rigid arms about the central axis.
There is also provided according to the teachings of the present invention, a universal wheel operated winch for convenient attachment to a wheel hub so as to draw a cable by rotation of the wheel, the universal wheel operated winch comprising: (a) a drum providing a substantially cylindrical outer surface configured for receiving a cable wound thereupon, the drum having a central axis; (b) at least one arcuate rod, rigidly interconnected with the drum, the at least one arcuate rod approximating to at least one are from a virtual circle of constant radius about the central axis; and (c) at least three rigid arms mechanically linked to the drum and terminating in an end portion configured to engage an edge of an aperture in a wheel hub, at least two of the rigid arms being mounted so as to be slidable along the at least one arcuate rod, thereby permitting adjustment of an angular spacing between at least two of the rigid arms about the central axis.
According to a further feature of the present invention, each of the at least three rigid arms is mechanically linked to the drum via a pivotal connection configured such that pivoting of the rigid arm varies a radial distance from the central axis to the end portion.
According to a further feature of the present invention, there is also provided a mechanical actuator associated with the drum and configured to impose a substantially uniform limitation on the radial distance of the end portion for each of the arms from the central axis.
According to a further feature of the present invention, there is also provided a mechanical actuator associated with the drum and configured to displace the at least three rigid arms pivotally about the pivotal connections to positions in which the end portion for each of the arms is at least a given minimum radial distance from the central axis.